Disk Cleanup can be particularly helpful to speed up things like malware and virus scans. Disk Cleanup deletes all kinds of unnecessary files and temporary information. It can free up a fairly significant amount of space and improve your system performance
Disk Cleanup can be found in your Start Menu under Accessories >> System Tools
You can also search for it in Start Search or Cortana by simply clicking start and typing "clean" or "disk cleanup". Or you can run it directly by pushing Windows Key + R and typing "cleanmgr" in the Run dialog.
However you get there, select your primary drive, which should actually be selected by default. You can do other drives later if you want. Push OK and it will scan for files that are no longer needed.
When it is done, simply check every category that you feel comfortable with. You really can feel comfortable checking all of them except perhaps, "Compress Old Files."
When you push OK, Windows will take care of deleting your web cache, windows update cache, etc. You might even free up a few Gb of storage.
